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EVP_PKEY_CTX_set_rsa_pss_keygen_md(3)                                  OpenSSL



NAME
       EVP_PKEY_CTX_set_rsa_pss_keygen_md,
       EVP_PKEY_CTX_set_rsa_pss_keygen_md_name,
       EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md,
       EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md_name,
       EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen - EVP_PKEY RSA-PSS algorithm
       support functions

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/rsa.h>

        int EVP_PKEY_CTX_set_rsa_pss_keygen_md(EVP_PKEY_CTX *pctx,
                                               const EVP_MD *md);
        int EVP_PKEY_CTX_set_rsa_pss_keygen_md_name(EVP_PKEY_CTX *ctx,
                                                    const char *mdname,
                                                    const char *mdprops);
        int EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md(EVP_PKEY_CTX *pctx,
                                                    const EVP_MD *md);
        int EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md_name(EVP_PKEY_CTX *pctx,
                                                         const char *mdname);
        int EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(EVP_PKEY_CTX *pctx,
                                                    int saltlen);

DESCRIPTION
       These are the functions that implement RSA-PSS(7).

   Signing and Verification
       The macro EVP_PKEY_CTX_set_rsa_padding() is supported but an error is
       returned if an attempt is made to set the padding mode to anything
       other than PSS. It is otherwise similar to the RSA version.

       The EVP_PKEY_CTX_set_rsa_pss_saltlen() macro is used to set the salt
       length.  If the key has usage restrictions then an error is returned if
       an attempt is made to set the salt length below the minimum value. It
       is otherwise similar to the RSA operation except detection of the salt
       length (using RSA_PSS_SALTLEN_AUTO) is not supported for verification
       if the key has usage restrictions.

       The EVP_PKEY_CTX_set_signature_md(3) and
       EVP_PKEY_CTX_set_rsa_mgf1_md(3) functions are used to set the digest
       and MGF1 algorithms respectively. If the key has usage restrictions
       then an error is returned if an attempt is made to set the digest to
       anything other than the restricted value. Otherwise these are similar
       to the RSA versions.

   Key Generation
       As with RSA key generation the EVP_PKEY_CTX_set_rsa_keygen_bits() and
       EVP_PKEY_CTX_set_rsa_keygen_pubexp() macros are supported for RSA-PSS:
       they have exactly the same meaning as for the RSA algorithm.

       Optional parameter restrictions can be specified when generating a PSS
       key.  If any restrictions are set (using the macros described below)
       then all parameters are restricted. For example, setting a minimum salt
       length also restricts the digest and MGF1 algorithms. If any
       restrictions are in place then they are reflected in the corresponding
       parameters of the public key when (for example) a certificate request
       is signed.

       EVP_PKEY_CTX_set_rsa_pss_keygen_md() restricts the digest algorithm the
       generated key can use to md.  EVP_PKEY_CTX_set_rsa_pss_keygen_md_name()
       does the same thing, but passes the algorithm by name rather than by
       EVP_MD.

       EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md() restricts the MGF1 algorithm
       the generated key can use to md.
       EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md_name() does the same thing, but
       passes the algorithm by name rather than by EVP_MD.

       EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen() restricts the minimum salt
       length to saltlen.

NOTES
       A context for the RSA-PSS algorithm can be obtained by calling:

        EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA_PSS, NULL);

RETURN VALUES
       All these functions return 1 for success and 0 or a negative value for
       failure.  In particular a return value of -2 indicates the operation is
       not supported by the public key algorithm.

SEE ALSO
       RSA-PSS(7), EVP_PKEY_CTX_new(3), EVP_PKEY_CTX_ctrl_str(3),
       EVP_PKEY_derive(3)

COPYRIGHT
       Copyright 2017-2021 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.



3.0.12                            2023-05-07
                                         EVP_PKEY_CTX_set_rsa_pss_keygen_md(3)